Fix production flows from parameter scenario's

[mrvisscher]

Parameter scenario's were giving unexpected results because all the flows that were being extracted from them were labeled as 'Technosphere'-types even though they could also be 'Production'-types. This lead to erroneous outcomes whenever the output flow of an activity has a formula.

• fixes Scenario LCA with different DB-Parameters gives odd LCIA-Results #1231

Checklist

• Keep pull requests small so they can be easily reviewed.
• Update the documentation, please follow the numpy style guide.
• Update tests.
• Categorize the PR by setting a good title and adding one of the labels:
  bug, feature, ui, change, documentation, breaking, ci
  as they show up in the changelog.
• Link this PR to related issues by using closing keywords.
• Add a milestone to the PR for the intended release.
• Request a review from another developer.

[coveralls]

coverage: 50.688%. remained the same
when pulling 7f7fcba on mrvisscher:parameter-scenario-flow-type-fix
into 0955df9 on LCA-ActivityBrowser:master.